Cannula



FIG. 1 is a right side elevation view of a new design for a cannula;

FIG. 2 is an enlarged view of a portion thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is an enlarged front elevation view thereof; and,

FIG. 7 is an enlarged rear elevation view thereof. 

CLAIM The ornamental design for a cannula, as shown and described. 